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ITI Showcase Webinar Archive

Crane Setup: Ground Condition Surveys & Stabilization Techniques

Crane Setup: Ground Condition Surveys & Stabilization Techniques

Enjoy the resources!  You will find the presentation pdf, video, and transcription of the webinar below. This webinar was originally recorded on January 22, 2014.

The January 2014 Edition of the Showcase Webinar Series featured Mike Walsh, President of the Dearborn Companies and focused on the importance of properly evaluating ground conditions and ground stabilization techniques in advance of mobile crane lifts.

Learning points include:

  • Need for Ground Condition Evaluations
  • Review of Crane Ground Pressures & Their Effects
  • Ground Condition Survey Technologies & Techniques
  • Ground Stabilization Techniques

Host: Mike Parnell, ITI President/CEO

Guest Speaker: Mike Walsh, President, The Dearborn Companies

Downloads:

 

TRANSCRIPTIon

Jonah: Today’s webinar is Ground Condition Surveys & Stabilization Techniques, which is a follow-up for an addendum to a webinar we held in November of 2013, with the help of Klaus Meissner, from Terex, on a Ground Conditions and Preparations for mobile cranes. So, I am very happy to have Mike Walsh, he’s the president of the Dearborn Companies, and he’s going to lead us today in the discussion. Just going over a couple of housekeeping items, before I turn things over to Mike.

Quickly, I just want to give everyone a brief introduction to ITI, if this is the first time you’re joining us. ITI is training and consulting organization. Cranes, rigging, lift management training; we have courses both at client locations and our three, state of the art, training centers. Our training is unique in the fact that it allows our students to learn theory in the classroom, the why, and apply it in the field by getting their hands dirty in actually doing what they’ve learned. We currently have a presence in the United States, Canada and Brazil. We have trainers in all three countries. We’ve done work on every continent except for Antarctica, because we will get there eventually. As you can see on the slides here, our expertise in cranes and rigging really pertains to a number of industries. Everybody and anybody who’s doing any sort of lifting or rigging activities, we can work with you. So to piggyback on the last slide a little bit, we are really proud to have worked with some of the best companies in the world. Looking over the registration numbers today, we have some of those folks on the line. I see a couple from Barnhart Crane and Rigging, a couple from BP, Chevron, Lurk, here locally, PG, and Portland, Oregon and then a few members from the U.S. Army Corp of Engineers, and many more. Lots of new people too. So glad to see that. Welcome, everybody. The showcase webinar series is a free monthly webinar that we put on to educate and better the industry. ITI President and Technical Director, Mike Parnell, is the host of the webinars. He tackles the single, industry topic and really in-depth, just shows the technical side of things and breaks it down in a way that anyone can understand. We often feature guest speakers, just like this month, and it’s really great to get additional information and light into the specific area of the crane and rigging industry. So today’s host is Devon Beasley, really lucky to have Devon on the line with us today. Mike Parnell, I have mentioned as usual host, he is still traveling, but Devon is a more than capable replacement. Devon has worked hand in hand with Mike over the course of ITI’s history; he brings so much knowledge, especially when it comes to crane and rigging, and heavy equipment. It’s reflected in the slide there, as you can see, in 2008 when he was selected as Top Trainer of the Year, according to Crane and Rigging Hotline magazine. So that’s quite an honor. Thanks, Devon.

As I mentioned earlier, we’re really honored to have Mike Walsh from the Dearborn Companies with us today. Mike’s a subject matter expert from Ground Conditions and Survey Techniques. Mike has had 30+ years’ experience and I can’t stress enough to thank Mike for his time and efforts today. So I am going to turn it over to Mike, in one second. I think everybody has heard enough from me, I am going to give the screen and control to Mike. Alright, it’s going a little slow, I am sorry for that, everyone. Mike, if you’re there, please takes it away.

Mike: Okay. Thanks, Jonah. Bear with me for just one second here, get things aligned up. Here we go. Well, anyways, thanks Jonah. Good morning, good afternoon, good evening – depending on where your location is. I’d like to start by thanking everyone for time and attention today, and I’d also like to thank Mike Parnell and his people at ITI for the opportunity to present. Quick look at our agenda for the presentation, just briefly introduce you to our firm. Run through some regulatory needs here in the U.S., as far as ground conditions and evaluations, and stabilization techniques. Also, just as Jonah indicated, the latest of the member at Terex’s, particularly Klaus Meissner, put on an outstanding webinar on ground effects and ground pressures. I’ve got a couple of, Klaus was kind enough to allow me to include a couple of slides for review purposes, and then we’re going to look at a kind of neat things in terms of some survey technologies and techniques, and also some state of the arts installation applications.

So, anyway, the one thing is – one of the focuses of today’s presentation is really on mobile cranes. It’s important to remember that, if you’re setting up a main crane, you can have assist cranes, telehandlers, but the ground conditions, while there may not be a regulatory driver behind every one of these, there’s a practical need to pay attention to these, or all of these. Everything through the foundations. So just a little FYI, to keep in the back of your mind, has progressed through this. Whatever ground conditions you have there for your client, your practice site, they impact a lot than just the cranes. So, Dearborn – we’re a 60 year-old engineering firm that is located in Suburban Chicago, we operate nationally in the U.S. and across North America. We’re a full-service engineering firm that has, we’d like to think it’s evolution, but we’re revolved now more towards a geometric surveying focus, predictive of particularly 3D utility acquisitions. This includes above ground, 3D laser scanning and modeling through 3D underground utility mapping, which has led us into crane placement surveys and lift planning. We also operate a non-destructive examination that has discretely serviced concrete companies. It’s kind of an outgrowth of ground and radar work that we’ve done. On the engineering side, we’re still designing, but we’ve become somewhat more focused in terms of specialized services that really go more into engineering for ground stabilization and cranes. Some of the folks we’ve worked for, we got some on the line here, and these are just a handful of utilities, energy companies, pipeline companies, briery over lappers that we worked for. Again, just a handful of some of the engineering and constructors that we also provide services to. Here, in Chicago, these are the primary crane companies that we have worked for. Again, just to give you a little bit of a flavor over there.

We’ve worked everything from ground surveys to 15 ton boom trucks up at super capacity, world of cranes- an indirect basis we’ve work, practice work Mammoet. This was a 12 pipe still, a new crude unit that’s just coming online at BP’s refinery of Whiting at Indiana. The cranes –we did all of the ground condition work in advance so that we’re on direct basis with BP and everything went swimmingly with that. Currently, a deep south is actually, I believe they’re in the throes of assembling a crane at the FCCU 600 at BP Whiting. Again, this is a project we were at a direct basis for BP, but the results were ultimately returned back to Deep South. So, give you bit of an idea of our span in terms of exposure and expertise, and in terms of the cranes we deal with. We do a lot in the central business district of Chicago, and actually, that’s how we were introduced to this world of ground condition surveys. Began at this somewhat benign looking, this is actually a glorified alley. It’s at Garland Court at central business district of Chicago. There was, something that we’ve been working with, it’s a national firm – a little bit of a problem. Set up a 500 ton crane and unbeknownst to them, there was a 12 foot deep, vaulted basement that extended out into the end of the alley. They had a punch-through and had a boom that caught the top of the building. The whole crane probably would have ended up in the basement. We were brought into this after, and we did survey this entire street- both in terms of using the radar, imaging, and also provided survey services to map all of the vaults, utility, manholes, and the like. Vaulted basements and went through a whole engineering  process in terms of the repair of the street, and also getting this permitted so that the contractor didn’t go back in, with the city’s approval, which they were ultimately able to do and they completed the list without incident. That was about 8 years ago, and that was our intro. Since that time, this contractor carried this around the country with their forklifts. So, that’s the background to Dearborn, we want to start to move into the meat of the presentation. For those of you in the states, we’re governed by OSHA, and a couple of years ago there was a first upgrade to 1926.1401 for quite some time, and one of the major changes in this was a shift in allocation liability. OSHA, in their regulations, established that the term – controlled panic and this controlling entity bears legal responsibility for insuring that the ground conditions are adequate and stable for operation of crane. This is a shift from where, back in the day, this was thrown at least – responsibilities were thrown on the back of the crane company, and ultimately shoved down to the operator. And while the operator still is the responsibility handling authority, right in the ground, in terms of whether they make a list or not, this controlling entity now takes on a legal liability in terms of the ground conditions of the site.

Responsibilities of this controlling entity is now responsible for ensuring the adequate ground conditions, and the definition of this, as far as who the controlling entity is, its employer to read this, whether it’s the contractor, general contractor, CM, or other entity that has overall responsibilities for construction for the project. This can be, basically, anybody from overall CM to especially trained contractor to fallback, a known operator, but somebody, at some point, is that controlling entity. The OSHA requirements for this controlling entity, number 1: they actually bear this responsibility to ensure that the necessary ground prep is bent, or formed, and the ground is in the firm graded sufficiently. They also bear the responsibility of informing the users, the operator, of any known hazards that are within the setup are of the crane. So this takes anything from voids, crusts’, to underground storage tanks, utilities, vaulted areas, any of those types of things, wall-in or the soil condition such that, if you got some really poor bearing capacity there, that information also needs to be controlled, be conveyed to the operator prior to operation of the crane. From there, this controlling entity is legally responsibility to ensure that whatever preparations need to be made is made so that the crane stays up. Well, the end, there is also end regulatory requirements. There’s a very practical need to know what your ground conditions are – make sure that they’re adequate for the equipment you’re going to place.

Most important, highest priority is always personal safety. We want everybody to go home, intact, basically, everything still attached to them at the end of the day. That’s first and foremost why we want to ensure that ground conditions are adequate. Recently, rigs here in the United States push some standards and Canada, across the world. We’re still dealing with accidents, so obviously, this is the crane. So I just want to show you an example of what can occur with an undetected ground condition. This happened last August in downtown Montreal, where the water back hose was a sinkhole that basically opened up with a significant water leak. Fortunately, there were no injuries or fatalities. We think the piece of equipment actually survived as well. But, given the magnitude of the leak, and apparently – they had other issues similar to this in the downtown area, somebody should have come and been aware of the potential of something like this and undertaken some type of investigation, other than basically proof-rolling the pavement by putting a piece of equipment out there. On a little more serious note, this goes back to last October, at least 140 ton lass boom crane that’s setting pre-k panels up at the twin city. Findings were that the vents out weren’t really adequate and additionally, I believe they didn’t have the outriggers fully extended as well, and ultimately, this tip over caused the crane operator’s life. With a little more recent event, down in Sao Paulo, Brazil, this one’s got some publicity as well. It was a new, luvre crawler crane, setting the last 30 or 32 500ton roof truss for the 2014 world cup stadium. There have been very significant rains these days for there were no mats deployed on the crawl, and set this last truss, crane tip. There were two fatalities that resulted in this. I don’t believe there’s been a formal finding by the Brazilian government. But, according to what I’ve heard from there that the ground conditions failure was the cause of the tip over.

Just, as I said, Terex and with Klaus Meissner, put on an outstanding presentation that really had some terrific information in terms of how cranes actually affect the ground and how you can see the types of displacement. I’m pretty sure this is still online and available through ITI. I would highly recommend you check this out. Again, Klaus was more than gracious enough to allow me to put a couple of the slides in here and just a little bit of a refresher. So we’re looking, in terms of ground surveys, obviously we’ve got effects of the crane are going to have on the ground. These can be symmetrical or asymmetrical, also, this is dynamic loading- what you’re seeing, so is some cranes slew over center of gravity shifts, so you’re seeing a constant change in terms of ground pressure across these. Even with crawlers, sometimes it’s forgotten, people see these big tracks and they don’t realize, in fact, you can point load, as you can see on the right, with the non-symmetrical loading, you can generate a point load on a track just as well you can on an outrigger. Again, create problems for the existing ground conditions. Mobile, altering crane, obviously we’re dealing with outriggers and some matting there. And again, these are dynamic loads we’re seeing different ground pressures under different conditions depending upon the weight, the radius that we’re picking through and even wind conditions can begin to alter this. Again, we have a situation where all of this, no pun intended, bears on the ground conditions.

Ground materials itself are the deciding factor here, depending upon what we got. We got from hard rock or reinforced pavement stand out, where we get to inorganic silts, we go from something that’s got outstanding bearing capacity to something that basically is soup. All of that, again, has to be taken into account as part of the planning of ground conditions and evaluation. Typical failures, as we’ve seen in a couple of these where we had excessive loading and results in ground pumping or displacement, and ultimate tip over of the crane and or vehicle. We had a garland court, and other locations, get a point load out of material, and result in a punch-through. Which again, will result in the tipping of the crane? Other things to be aware of, is that these ground pressures are exerted, whether you’re near an excavation or at an embankment. There’s a somewhat widely reviewed video of a crane, I believe in New Zealand where they were setting a bridge gird, and another situation where there’ve been fair amount of rain prior to the days before this, and as they made the lift, you can see the ground give way and basically, the embankment just slushes off, and the crane and the operator, effectively, rolled to the river. Again, elements to be concerned about as far as awareness with where you set your crane.

In a plant environment, or in a urban environment, you’ve got utilities, building foundation, tunnels somewhere in this, and as a crane picks up its counterweight, fix up the load, and these ground pressures begin to come on, there’s a lateral pressure surcharge that’s applied to mixed foundations, structures. While you may not exert enough pressure to or that if the utility manhole or vault may not have tipped the crane, at the end of the day, there’s still that damage you have to pay for the replacement that structure. Obviously, if it’s a building foundation, it can undermine structural integrity building, and it’s pretty expensive. Invasive operation, you have to go back and repair the foundation or tunnel and undercuts. So, additional consideration. Again, you can have a fairly crowded environment under the ground if you are in an urban area, also, a gentle reminder that there may be something other than utilities that are there to bite you. Again, it depends on what kind of court. So, onto some survey technologies and techniques.

This is included: what not to do. There’s no scientific basis, so we certainly don’t recommend reaching sticks or dousing as the means of locating, whether it’s ground water or trying to find the utilities. There are far more scientific technologies that are out there, these are more along the lines of geophysical arena, which is a man base of means and it can be anything from conventional utility locating technique to ground factory radar, which is the upper center electromagnetic induction on the right upper. It can also be anything from the standpoint of remote television, visual inspection and just good old fashioned survey technician as well. Speaking of the geophysical methods in terms of ground conditions are concerned, cranes we found to be our primary tool of choice, is ground penetrating radar or GPR. This is a truly benign, non-destructive means. There are health effects, no interferences from the radars, telemetries, or anything like. It is an actual radar, it is radio-frequency microwave that’s pulsed into the material in the ground, it’s up in the air, in the submarines, x-ray, we’re not running around with no underwear, it is actual radar. The image of this, it gives us a true 3D view of what’s below, we’re getting, able to pull, depending on where, reflection from a target or by a change in wave velocity, we’re able to get a determination of what’s beneath this. We’re also able to tie this down on a coordinate basis. Key to this too is to detect non-metallic. If you have, in as far as utilities are concerned, there’s classic type THPE/PEC or unfit clay, reinforced concrete type pipe burst PVC, you will be able to image those and detect those. You’ll also be able to image concrete foundations, railroad ties and the like. Some will come across different materials so if you’re using something along the lines of electromagnetic induction, there you’ll need various materials to work with no response. One of the other things that I touched on is change in wave velocity; we can determine areas unconsolidated soils or voids, crusts, by a change in wave velocity that we detect. The one hold back on this is that you cannot determine bearing capacity with GPR. There’s no algorithm that is out there, this is one of the grails that actually tried to upload but there’s no way to correlate the radar data to the actual ground bearing activity.

So you have to move from a geophysical method to a geotactical method to get bearing capacities. This is some sample GPR data, what you’re seeing in the center is actually a depth slice, we’re able to peel the data like an onion, get down to where we find basically – the most representative view, and we’ll annotate that with the gray areas that you’re seeing inside, that are actually called the raw data. This is where we’ll get return. This is also where you have to have enough expertise in terms of being able to identify and use some other investigative techniques as far as what these returns actually indicate. There’s nothing magic, with radar that’s going to differentiate the storm sewer from sanitary sewer from water lines, gas mains, process pipe or pipelines, you’ve got to use other investigative technique methods to make those determinations. But we can, in fact, determine areas of disturbed soils and also voids. Actual collection, we collect data typically using bidirectional grid. The basis for that is physics of the radar is such that the closer to the right angle, perpendicular to whatever your target is, you’re going to get a stronger return. So, if you got anything that’s running through an area, at a diagonal – by running two directions across it, you got a better chance at attacking both. The interval, data collection interval, how far apart we space our lines are really dependent upon size of the particle that we’re searching for. So if we’re looking for underground storage tanks, 20,000 gallon tank, we can run a far, wider interval than if we were looking for an 8-inch pipe. Same depending on the size of the casts, or areas of suspect soil or voids that will also be true, also draw the data collection interval.

As far as getting into bearing capacities, there are some other tests that rather than a full-blown sampling, you can use a static plate load test – which is ESPM method. This is more for pavements, however. Will you give you an idea of sheer strength. A proctor test is going to give you some soil density information, which you can translate the bearing capacity, but this is based primarily on moisture content. So you’re going to get more ball-park data with this than the actual firm information. So if you’ve got an area where you got real concern with the actual bearing capacity, this is where you’re going into technical test method. Parana is water test and this is where you’re going to look at the blow count, as they drive the sampling spoon down, and corralling that to actual bearing capacity and soils themselves that are analyzed and characterized – which gives an idea of not just the bearing capacity but you also get an understanding of the geology of this feat. No matter what you do, in terms of data collection, whatever method that you use, it’s critical that you georeference this. By that, you have it tied down to some means. Again, when we are all through when we collect this data, we’re also going to overlay crane to it. We need to be able to know how that crane relates to the data that we’ve collected. This isn’t horseshoes and needs, it doesn’t matter where – we can just slide the crane down and move it 10 ft. we got to know, from a an accurate and precise basis, as to where the center pin of that crane is going to link to whatever the soil condition and utility information that we collect.

Being able to collect the data and tie that down, identify the grids, geo-referenced and tied down whatever utilities are out there, circles the ultimate analysis that is going to take place. This goes to some of the documentation, this is project here in Chicago that we did for a 500t crane and 500 Luvre mobile for Stevens and also part of a project for Chicago transit, not only did we have utilities to contend with, but we also got two subway tunnels that are running beneath the  crane as well. So being able to locate this – we actually in concert with the crane company, we ultimately needed to move the crane 6 ft. to clear some of the utilities, and all that added a factor in the lift planning. This is where, again, some of the documentation will provide also, the crane overlaid on the radar data so that all of the stakeholders have an idea, the crane needs to move, why? The end game of this is really to get adequate, as is, conditions documented, add a safety component to those, and then do a comparative analysis as far as the, in terms of what the imposed loads are. Also, in performing this analysis ,it goes to beyond just simple look of the geophysical achievement, technical aspect, but there’s got to be an understanding of the lifting and rigging operations, also practical considerations. For any ground improvements, movements going to be made and so on in the end, but while performing the survey and collecting the data, it’s a fee stack to the ultimate analysis, and that ultimate analysis needs to be a blend of engineering and science, and constructability experiment. So, obviously if we got adequate conditions, we can go ahead with what we’re going to do. But, when we get in the area of inadequate ground conditions, I only got three on the slide, but there should be a fourth – don’t make the lift, but usually isn’t a viable option. One option is based on the way of what you have available bearing capacity is lighten the load, either modularized it or break it down if you’re flying steel to the top of the building. Maybe the fabricator can read the sign, some of the steel sizes, reduce the load, reduce the amount of steel that you’re going to fly in a single lift. If it’s process related, you may be able to break down the module, extract some equipment out of it. But, obviously, there’s an economic analysis that plays into this as well, because now, while you’re making it easier for that crane to make that lift, you now are adding to whatever your fabrication costs are, your assembling, final installation costs, and also schedule to pick on the construction site. So if lightening the load isn’t a really viable option, probably the best option is at least try and find a better distribution of ground pressure.

That’s effectively just increasing the foot-print of the lift by increasing square footage of mats , so this is putting down additional matting, load plates, and we’re basically turning around, spread the load over a wider area. Last consideration is an actual modification of the ground conditions –which, may actually be achievable. Again, as far as better distribution, of the load, there are a variety of ways of using synthetic mats, wood mats, steel mats, so there’s that or any combination of these that you may be able to employ. That takes care of the distribution side of it, or at least, on a superficial level. As far as ground modification techniques, it can be simple grading or soils or possibly the addition of backfill and aggregates to ensure that you got a level area to work with. It could also be the addition of geofabrics, which are going to give you some increased bearing capacity, better soil capacity. Once you had exhausted those from ground modifications concern, now the next is to look at ground densification of soils. Two primary means of densification, increase density of those soils is ether through compaction or consolidation of those soils.

With compaction, effectively what we’re doing is we’re just rearranging the soil particles, we’re getting moved in, tighter to one another without an outflow of water. That’s achieved by some application of mechanical engineering. So, it can be with a sheep roller as you’ve seen with the picture here, smooth drum roller, vibratory compaction there’s any number of ways that should go about achieving this. Consolidation is really primarily used for more of a clay typed soil, effectively what we’re looking to do is remove the water and increase the density of the clay by moving that water and squeezing it out of its pores to lighten the load. If you can get a bigger area that you’re looking at, you may be able to utilize dynamic compaction, obviously, and there is the ground condition adequate to where you can crawler out there tamper with the counterweight on it. But, this would be more of a case where you got either a super capacity crane working on this, or if you’re really looking to improve the lay down area for wide varieties. One of the advantages to dynamic compaction is you can get some really deep compaction with this, depending upon the weight of the tamper and draw pipe, you can get compactions as deep as 10 meters. So again, in this case, what you do is go through this type of compaction and look the backfill of the craters with pick material, grade it out, utilize that as your bet. Beyond this, you can go to the extent with the installation of concrete foundations for the crane to bear it. You can get applications where you need to drive sheep piles along the perimeter to try and contain soils if you’re pumped and displaced. We had a situation here in Chicago, on a turnkey basis, we actually ended up excavating down 12 ft. on a site for 8 outrigger locations. Backfilling those with 3-inch rock and some trench boxes to contain the 3 inch rock and top that out with wood mats and steel mats. There’s any number of varieties, ways that you can attack the ground conditions, but it all has to come down to a solid evaluation of what your conditions are, and what are the most cost-effective method to achieve bearing capacities that you need. So, the saying is “you’re only as strong as the ground your stand on,” that holds true for the types of equipment that we’re looking to deploying here.

At this point, it concludes the formal part of my spiel – I guess we can take some questions. Again, like to thank everyone for your time and kind attention. Once again, thanks, the fine folks at ITI for the opportunity to present today. So, Jonah, Devon, don’t know who’s going to grab it from here.

Jonah: Sure. Thanks so much, Mike. It’s great information. We do have a few questions that came in. I am going to pass the screen over to Devon here, just in case he wants to add something that you or himself answers on. Let’s get to these. I want to respect everyone’s time, so we won’t go too long, but we do have some good questions that came in. So, we’ll get right to it. Mike or Devon, the first one is: This is from Yannick, he just wants to know if, off the top of your head, if you know of any reference books that he can access to get calculations for ground bearings and pressure. So whoever wants to take that one?

Mike: There are some soil mechanic handbooks that are out there. There are a variety of different sources. Probably the best thing to do would be to contact a geotactical firm that’s in your vicinity or the project’s vicinity and ask them for whatever reference information they may have. I know that’s not exactly a really specific answer- I’m trying to think, off the top of my head, as far as a handbook or source to be able to get. I can certainly research that and send that answer out.

Jonah: Sure. No problem. We can get that to Yannick via e-mail, after the presentation, get a chance to digest everything. So, the next question.

Devon: Jonah.

Jonah: Yeah, go ahead.

Devon: There’s a book we used to have in our bookstore called crane stability and it’s based on soil conditions and kind of an engineering book that shows you how to determine the outrigger pad underneath the crane pad itself. That might be of some interest. It’s called Crane Stability. We don’t have in our catalog store anymore, but that might be of interest to some of the listeners.

Jonah: Yes. Thanks, Devon. Great. So we got some information there. I’ll move on to the next question, this one’s from Jim. He asks: as most crane lifts are very short duration activities, how do you address this rather than going with the long term bearing results used for permanent structures?

Mike: This is one of the things that you get into and it can be a bit of an engineering debate, but depending upon who’s involved, it may be the owner, it may be the owner’s design engineer, but a lot of times you get this, you’ll get the situation if you’re looking for bearing capacity as if, you put the foundation and it could support a 10-story building. Obviously, this is 10 points out. These are short term loads that are being imposed. It usually, there’s a certain amount of back and forth, I don’t think that there’s, again, a cookbook response to this. You got to be able to sit down with them and demonstrate in terms of what the loads, the calculation of the loads, are going to be based on the data that you get based on the crane and the crane provider. And, what you have in the way of soil capacity, and try to reach for an understanding. Me, again you can go to some better distribution to manning and so on to reduce it, a lot of times, this gets into some of the safety factors. We’ve had a couple of situations where we’ve been gone and assumed that you got a bearing capacity of this, and I’m you know, that was the bearing capacity knee deep in the ground. I weigh 230 pounds, and obviously, the grounds in better condition than that, so, it becomes a matter of experience and also an engineering debate. That as far as it being able to get resolved.

Devon: we can say our soil conditions and what lies beneath that soil becomes very critical in what we’re doing. Obviously the footprint size becomes an advantage to us, but soil conditions and the compaction of it is really the key.

Mike: Right. This is where it is too, if this is an assumption that, say, the owners in this case are whoever, and it starts to raise the issue, if there’s a big differential of what their assumption is, in terms of the soil conditions are versus what your assumption is, that’s where you may need to go to tests, you may need to take some soil and get some empirical data. Utilize that as far as your final analysis, how to support the crane.

Devon: Okay.

Jonah: All right, thanks guys. Let’s move on to the next one. This is from Mark, it came in during the portion of the presentation that talked about micro-radiation, he’s wondering if any PPE is needed to protect against any radiation.

Mike: Okay, there is no radiation. There is no PPE requirement other than whatever the site PPE is. So, there’s nothing specific to, as far as radars are concerned. This isn’t putting yourself in a microwave oven, these are relatively low energy pulse that’s being pushed in. There are only so many frequencies but, in terms of the actual energy that’s being conveyed, it’s not that great. There’s no need for any type of evaluation. There’s not like if you got x-ray, these are x-rays used for imaging of concrete, you’ll have evacuation in areas where you can’t, don’t have anybody above the floor, below – it might be a 40 ft. diameter, 44 radius of where the x-ray is going to be taken. You have none of that with GPR. It’s, there’s no interference, you have the system operating and run it over your body and you’re going to have zero health affects drawn.

Jonah: Just a quick follow-up to that question, Mike or Devon. Mark was wondering if people with a pacemaker can work with a radar unit.

Mike: You know, off the top of my head, I would think they could. I’m not a doctor, I don’t play one on TV. I would recommend that whoever has the pacemaker, they discuss it with their doctor and the equipment manufacturer. The best of my knowledge, we utilize on the concrete MPV side, we use this equipment in occupied areas all the time. Hospital settings, where we got patients on the floor, below, we got them in room next door, you can have people scanning right on top of the scanners. No interference with any of the telemetry equipment, we utilize in airport settings, scientific laboratory, so there’s no interference with other radars or radio systems. It’s been pretty benign. Given the obvious  health implications with this, you do some additional research on this and get it cleared with your doctor and manufacturer.

Devon: I agree with that. I have a defibrillator implant that’s ICD, as I wrote on the screen there, and certain powers of magnets of wires can control stuff, I got to be careful and not get too close or it affects it. And it could change the settings, which can make it go off, and that could be serious issue.

Mike: Yes, sir. Absolutely. So, now again, I would hardly recommend, check with your doctor and also with the manufacturer. If Mark wants some information on manufacturer, system manufacturers, we can get in contact with some folks.

Jonah: Okay. Thanks, guys. That’s certainly special case there, but good question nonetheless. We’re approaching an hour here, and again, like we said, I want to respect everyone’s time. So, there are actually a lot of questions coming in, I’m going to do the best I can to get you guys an answer via e-mail. Either from Mike, or Devon, or somebody from our office. I’ll get you the best answer that we can. I’m going to end it by this final question. It comes from Mike, and he is wondering, what safety factors do you recommend in the design of outrigger pads or crane mats?

Mike: Okay, is this – I’m not really sure what he’s talking about – the mat itself, or?

Jonah: As the question came in, for the design of the pats for the outrigger mats themselves, yes.

Mike: a lot of times – I’m not really 100 percent clear on whether it’s the actual design factor that’s installed or for in the application of the mats, what kind of safety factor you’re looking at. The safety factor there, if we’re looking at how it relates to the crane, again, the first thing we’re going to talk to the owner. Whoever’s got control of the site. If we’re in a plain setting, some known operator that’s BP or Chrysler Mill or someone else like, they may in fact have standard procedures, and they’re going to turn around and tell you. You’ll turn around and say, based on the mat this size, we’re going to be applying so many pounds per square foot, and they’re going to tell you – look, in our facility, the maximum weight distribution we’re going to allow is going to be so many pounds per square foot. At that point, you’re going to have to increase your manning or find a way to decrease the load to achieve that. It’s, a lot of that too is going to come back to the actual crane providers themselves. Based on their interaction with the crane manufacturer, that’s not necessarily something we would specify. It’s more of something we would seek to get their information from the crane provider and/or the owner operator of the site.

Devon: there are some companies out that make the composites style or type of outrigger blocking, Dykon is one that comes to mind. They might be able to provide some of that information or be able to direct them in the right way as to what they should get or use. We all know, whatever the material is, it’s got to be strong enough if there’s any gap underneath that pad. That it’s strong enough to expand that gap, without breaking.

Mike: Yeah, or even necessarily deflecting that, just the deflection of that can be enough to throw the center of gravity off and get the crane to tip. Again, if he’s looking for more information on the mats themselves, to be able to go to the mat manufacturers, here in Chicago we got Sterling Lumber if you’re looking for wood mat information. I know they all distribute nationally, so. In the synthetics, there’s a wide variety of manufacturers out there.

Devon: Yes. Sure.

Jonah: Thanks, Mike and Devon.

Mike: Really quick, I know Carrey and Kevin Kohlberg are on call right now from DICA, it might be worth a try, I can actually  want to try, don’t know if they have speakers set up. But like you said, there are some out of the manufacturer, and their design factors. I’m looking at Dykon’s website right now, and they have a fit system that actually helps fitting cranes to the, crane pads to the crane and as well as to the site they are working at. So anyway, they probably can answer that question, and we can Jonah, I’m sure you got a lot of questions that we can summarize. We’ll have Carrey and Kevin answers that and sends that out with the summary. That’s a great question.

Zack: At this point, guys, I’m going to turn it back over to Jonah. I think we’re all wrapped up. This is Zack, by the way, everybody. I appreciate you all coming and Mike, thank you very much. I know we’re going to get on the call after this. Awesome, awesome presentations. You got the really good comments coming in. So thank you very much.

Mike: Thank you.

Jonah: Okay, everyone. Again, thank you, Mike, for everything. I’m going to grab control of the screen back here, really quick. I know, certainly is not local to everyone, but I want to let everybody know about an event that is coming up that Mike will be in attendance as well as Mike Parnell, a bunch of representative from ITI at the Heavy Rigging and Transport Lifting Workshop coming up February 19th, to the 21st in Houston. A bunch of great presentations. Both Mike Walsh and Mike Parnell will be there, as I said, Jim Yates from Barnhart, Michael Vandall from Works International, the thought leader in heavy rigging and transport industry. Keith from Bechtel, just a great speaker lineup. So, if you guys have some time, check it out. It’s heavytransportworkshop.com, or your can find it at the ITI website as well. If you have any questions, let me know, my e-mail is Jonah@iti.com ,so thanks everybody and I apologize for not getting to all the questions, but again, I will be following up with you privately. So thanks so much, everyone.